Faulty ATI graphics cards blamed for hardware glitches have forced Apple to push back all shipments of the 27-inch dream machines at least two weeks, resellers said.

Apple has delayed shipments of the 27-inch Core i5 and Core i7 iMacs by one to two weeks amid mounting complaints of various graphics-related glitches, Computerworld has learned from two independent European authorized resellers. The publication has been able to confirm the delay with several US-based online resellers as well, including Mac Connection and ClubMac.

Apple’s US online store currently has a two-week delivery estimate on both iMac models, up from 5-7 days. Note this could as well reflect a potential surge of the iMac demand expected in the holiday season. Amazon’s delivery estimate for the affected units is between 1-2 months.

Both 27-inch Core i5 and Core i7 iMac models utilize AMD’s ATI Radeon HD 4670 and Radeon HD 4850 discreet graphic chips, respectively. Interestingly, an October report claimed that Apple gulped the entire holiday supply of the ATI Radeon 4000 series GPUs, causing shortages in the industry by securing a 60-day worth output of the ATI Radeon 4850 chips. This indicates that Apple had estimated a high demand for its top-of-the-line 27-inch iMacs.

As Geek reported, an unknown portion of new iMacs are plagued with a number of issues, including strange dog-whistle noises, hard drive failures, screen flickering, and yellow tinted displays. According to posts on Apple’s support forum (here and here), the affected machines exhibit random flickering that looks like a horizontal bar of about 2-3 inches just popping in and out of the screen. True to its form, Apple hasn’t publicly commented on any of this yet and has remained mum on its own support forum. Such an ignorance has enraged a Los Angeles-based forum user named Merle Rideout who wrote the following:

Where is Apple’s response? The silence is deafening. I’ve been reading this thread with interest and despair. I’m having the same problems as everyone else. The silence from Apple is unconscionable.

To make matters worse, some users received their iMacs in less than pristine condition: Some units arrived DOA (Dead On Arrival) and wouldn’t even boot while others came in with shattered displays. This was enough to prompt Bedford, Nova Scotia, UK-based web designer Scott Pronych, whose iMac arrived with a cracked glass display in the lower left-hand corner, to launch imac.squeaked.com where customers can report issues with late-2009 iMacs. At press time, over 600 reports have been filed by users worldwide, but only 10 percent from owners of 21.5-inch iMacs. A thread on Apple’s support forum packs in 1,200 separate messages with a total view count nearing 200,000.

Christian’s Opinion

It appears that problems with new iMacs might be more widespread than originally thought. More troubling than that is the fact that we know nothing about the scope of this serious issue. Who knows how many people got faulty iMacs beyond those who have logged theirs on the Squeaked site. The good news is that Apple seems to be replacing faulty machines – even those with cracked displays – without asking too much questions. The bad news: those unfortunate customers will now have to wait at least two weeks for their dream machine replacement.

Assuming at least 1,000 units need to be replaced, that’s potentially $2 million in revenues, based on the $1,999 price of the 27-inch Core i7 iMac. Of course, manufacturing costs are significantly less, but it still translates into a notable sum. Worse than the money loss is bad press threatening to snowball into a PR catastrophe. I know I’ll be waiting until Apple sorts out this mess before I order my 27-incher.